Optical metabolic imaging of humans using two-photon FLIM

The first clinical study of two-photon FLIM has been performed in Jena in 2003 on patients suffering from malignant melanoma. NADH has been imaged by time-correlated single photon counting and 80 MHz femtosecond laser excitation. Studies with a tunable Ti:sapphire for NADH/flavins excitation have been conducted on patients suffering from dermatitis, psoriasis, and cancer. Optical metabolic imaging has been also performed on brain during glioma surgery and on volunteers during oxygen inhalation using an ultracompact Er:doped fiber laser. Five astronauts prior and after long-term space flights have been investigated. "Energizing" cosmetics with oxygen scavengers was found to change the ratio free NADH to bound NADH.